Abstract # 124:

RECEIVING SOCIAL PLAY DURING THE JUVENILE PERIOD IS NEGATIVELY ASSOCIATED WITH REGULATION OF HYPOTHALAMIC-PITUITARY-ADRENAL (HPA) AXIS IN RESPONSE TO SOCIAL SEPARATION IN CAPTIVE WHITE-FACED MARMOSETS (CALLITHRIX GEOFFROYI)

The early social environment can affect how an animal regulates its hypothalamic-pituitary-adrenal (HPA) axis response to stressors. Here we evaluate the association between juvenile social play and HPA responses to social separation in marmosets. We predicted that animals engaging in more play in their natal groups as juveniles (5-10 months) would have blunted HPA responses and better HPA regulation after returning to their natal groups than animals that engaged in less juvenile play. Animals (N=26) were separated for 8 hours from their natal groups at ages 6, 12, and 18 months. We monitored urinary CORT levels before (baseline), during, and after separation with an enzyme immunoassay. Partial correlations controlling for family size were calculated between rates of play during the juvenile period and HPA reactivity (maximum CORT subtracted from baseline), area under the curve (AUC), and HPA regulation (post separation CORT subtracted from baseline). There was no association between baseline CORT or HPA reactivity and any measure of play (r’s?|.37|, p’s?.07). However, the number of play initiations received from other group members, but not play initiations of the focal animal, was significantly and negatively associated with AUC and HPA regulation at virtually every time point of separation (r’s?-.404, p’s?.05). Results suggest that being the recipient of social play early in life can facilitate regulation of the HPA axis.